.

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
22­
DEC­
2004
MEMORANDUM
SUBJECT:
Ametryn.
HED
Response
to
Error­
Only
Registrant
Comments
on
the
Ametryn
Preliminary
RED,
PC
Code
080801;
DP
Barcodes
D307099
and
D311641.

From:
William
H.
Donovan,
Ph.
D.,
Chemist
John
Doherty,
Ph.
D.,
Toxicologist
Robert
Travaglini,
Chemist
Reregistration
Branch
3
Health
Effects
Division
[
7509C]

Through:
Danette
Drew,
Branch
Senior
Scientist
Reregistration
Branch
3
Health
Effects
Division
[
7509C]

To:
Mark
T.
Howard,
Chemical
Review
Manager
Reregistration
Branch
3
Special
Review
and
Reregistration
Division
[
7508C]

Syngenta
Crop
Protection,
Inc.
has
provided
error­
only
comments
for
the
ametryn
preliminary
RED
and
the
product
chemistry
chapter.
For
the
purposes
of
the
present
memo,
HED
will
provide
a
point­
by­
point
response
to
each
comment
provided
by
the
registrant.
A
revised
preliminary
risk
assessment
document
incorporating
the
comments
below
will
be
issued
in
a
separate
memo
under
DP
Barcode
D307100.
Separate
memos
revising
the
product
chemistry
and
ORE
chapters
will
also
be
forthcoming
under
DP
Barcodes
D311642
and
D311600,
respectively.
.
Error­
only
comments
on
the
ametryn
product
chemistry
chapter:
12/
6/
04
letter
from
Syngenta.

Syngenta
Comment:
Syngenta
noted
that
MRID
40877301
contains
the
UV/
VIS
spectrum
for
ametryn.
Thus,
the
UV/
VIS
data
requirement
has
already
been
fulfilled.

HED
Response:
HED
has
confirmed
that
these
data
are
present
in
MRID
40877301
and
that
they
meet
the
requirement
of
guideline
number
830.7050.
Accordingly,
the
product
chemistry
chapter
will
be
revised
to
show
that
the
UV/
VIS
data
requirement
has
been
fulfilled
for
ametryn.

Error­
only
comments
on
the
ametryn
preliminary
risk
assessment:
12/
6/
04
letter
from
Syngenta.

Syngenta
Comment
1.
Syngenta
noted
that
the
surface
and
ground
water
EDWC
values
for
corn
are
below
the
cancer
DWLOC
value
discussed
on
pg.
38
of
the
document.
As
a
result,
the
use
of
ametryn
on
corn
appears
to
pass,
instead
of
fail,
the
screening
level
dietary
cancer
risk
assessment.

HED
Response:
Following
consultation
with
EFED,
HED
has
updated
the
corn
surface
water
EDWC
values
to
7.6
and
5.4
ppb
for
the
chronic
and
cancer
scenarios,
respectively.
With
these
changes,
HED
finds
the
original
charaterization
made
on
pg.
38
to
be
appropriate.

Syngenta
Comment
2.
Syngenta
questions
how
occupational
exposure
scenarios
listed
as
"
no
data"
can
be
determined
to
have
MOEs
of
less
than
100.

HED
Response:
HED
concurs
that
MOEs
cannot
be
determined
for
the
two
scenarios
listed
as
"
no
data".
Accordingly,
the
characterization
on
pg.
42
will
be
revised
to
clarify
that
only
one
scenario
has
an
MOE
<
100
and
that
two
cannot
be
determined
at
baseline
or
PPE1
protection
levels.

Syngenta
Comment
3.
Syngenta
contends
that
the
additional
information
about
testicular/
epididymal
tumors
contained
in
the
9/
17/
2004
CARC
report
should
be
added
to
the
"
Carcinogenicity
Evaluation"
paragraph
on
pg.
14.

HED
Response:
HED
concurs
that
it
is
appropriate
to
add
this
qualification
to
the
risk
assessment
document
and
will
make
this
addition.

Syngenta
Comment
4.
Syngenta
noted
a
discrepancy
exists
between
the
9/
17/
2004
CARC
report
and
the
ametryn
risk
assessment
document
concerning
the
need
for
a
forward
gene
mutation
assay
in
mammalian
cell
cultures.

HED
Response:
HED
concurs
that
the
study
in
question
should
be
listed
under
the
data
gap
section
of
the
risk
assessment
document
on
page
55.
This
change
will
be
made
and
should
remove
any
appearance
of
a
discrepancy
between
the
CARC
report
and
the
ametryn
risk
assessment
document
concerning
the
need
for
this
study.
.
Error­
only
comments
on
the
ametryn
preliminary
risk
assessment
and
occupational
exposure
chapter:
12/
17/
04
letter
from
Syngenta.

Syngenta
Comment
5.
In
a
separate
letter,
Syngenta
noted
that
the
occupational
risk
assessment
was
based
on
direct
label
use
rates,
without
making
the
proper
correction
to
reflect
80%
active
ingredient.
This
correction
is
needed
for
sugarcane,
corn,
and
pineapple.

HED
Response:
HED
agrees
that
the
correction
factor
of
80%
for
active
ingredient
should
be
included
in
the
occupational
exposure
assessment.
The
occupational
exposure
chapter
and
the
appropriate
sections
of
the
risk
assessment
document
will
be
revised
to
reflect
this
change
for
all
three
crops.

cc:
W.
Donovan,
J.
Doherty,
R.
Travaglini
RDI:
D.
Drew
(
12/
22/
04)
